Thermal cut-out.



No. 891,414. PATENTED JUNE 23, 1908.

0. A. ERNST. THERMAL OUT-OUT.

APPLICATION FILED APR. 6.1904.

w ltnesses'. lhventor". Charles fLErnst CHARLES A. ERNST,

OE SCHENEGTADY, NEW YORK, ASSIGNOR T0 GENERAL COMPANY, A CORPORATION OF NEW YORK.

TI'IZEERMAL GUT-GUT.

its. semis.

The present. invention-relates to thermal cut=out devices ior protecting electrical apparatus from abnormal currents, and more particularly to the class of such cut-out devices commonly known as indicator fuses.

The objection to most all of the indicator fuses now on the market is that the flash of the small auxiliary wire isnnconfined and,. as a consequence, the particles of molten metal thrown out upon blends of the anxiliar fuse are liable to i nite light combustih es in the vicinity of t e cut-out device.

I have found that by inclosing the indicator Wire by a layer of stout transparent insulating material, and providing a certain amount of space into which the ases of explosion may expandfslightly, this objection is effectually overcome and the facility with which the condition of the indicator wire may be discerned in no Way impaired.

In the accompanying drawing, forming a part of this, snecification and showing one embodiment, cl my invention, Figure l is a central cross -section. of a cartridge use drawn to a large scale; Fig. 2 is a plan; Fig. 3 is a longitudinal section; and Fig. 4 is an enlarged longitudinal section thereof.

The casing consists of a tube 1 of tough fiber or other insulating material provided with metallic caps or end pieces 2, which Yserve as the terminals of the main fuse mem er 3; i

The auxiliary or indicator fuse member 4-: is connected in parallel with the main inse member 3, and has a portion of its length ex- "posed to view outside the casing by thread? ing out through a hole 5 and back through a second hole 6 srranged some distance apart one side of the time i.

Over the portion of the auxiliary fuse member 4 exposed to the outside of the cats ing is. placed a sheet of mice 7 end over the Specification of Letters Patent.

Application filed April Q, 19%.

Patented dime 23, 1968 Eeriai H0. 201,2;28.

or other "fibrous material 8, centra 1y apertnred at 9, and securely pasted to the outside of the tube 1. By this arrangement sealed air chambers 1G are provided on both sides or" the indicator -fuse wire a, for the reception of the gases and particles of molten metal.

The space W tnin the casing not occupied by the fuse members is preferably filled with an absorbent material 11. apparent that the 'air spaces can he mice is laced a lar er sheet of ten h a er formed in other ways, as by removal of pertions of the tube 1 at the sides of the wire e, or by supporting the transparent sheet '7 out of contact with the Wire. i'liccordingly i do not desire to restrict myself to the particular arrangement of parts here n described and shown. I

What 1 claim as new and desire to secure by Letters Fatent of the United States, is:

1. A. thermal cut-out comprising casing, 9. main fuse member located Within said casing, an auxiliaryor indicator fuse member: connected in parallel with said main fuse member and having a portion of its length exposed on the outside of said casin a sheet of transparent insulating inateria l placed over the exposed ortion of said auxiliary fuse member, an an apertured sheet of fibrous material secured to said cas ng over said sheet of transparent insulating material.

2. A thermal cut-out comprising a casing, a main fuse member located within said casing, an auxiliary or indicator fuse member connected in parallel with said main iiise member and having a portion of its length exposed on the outside of said casins a sheet of transparent insulating rneterim placed over the exposed portion said auxiliary fuse member, and 'apertured sheet secured to said casing over said sheet of trans-- parent insulating material.

in witness whereof i have hereunto set my hand this day of .ipril, 1904:.

CHARLES A. ERNST.

itnesses:

BENJAMIN B. HULL, Hats-N Gsr-onn.

it is oi course 

